Gol'd-m in ing Copper. 155 



38. Gold, the most precious of all the metals 

 is found not only in deep mines like those of 

 iron, coal, or silver 



39. It has been found in the sands of streams, 



into which it has been carried 

 from the crumbling rocks by 

 rains, and from which it is ob- 

 tained by washing. Consider- 

 able gold is obtained by direct- 

 ing a powerful stream of water 

 a g a inst the rocks by means of a 

 hose, which is supplied from large collections of 

 water on higher ground. This is called hydrau- 

 lic mining. 



40. Pure gold is too soft for general use, there- 

 fore it is mixed with silver or copper, which are 

 harder ; it is then said to be alloyed, or reduced 

 in purity. 



41. For gilding, a portion of gold is ham- 

 mered out into leaves so thin that several hun- 

 dred of them together would be no thicker than 

 one of the leaves of your book. 



42. California, Nevada, and Australia 

 have long been celebrated for gold. 



43. Copper ore is found in several countries 

 and States, especially in the Republic of 

 Chili and in the State of Michigan, along- 

 the shores of Lake Superior. 



